Collaborative studies will be undertaken at Northwestern University Medical School (Chicago) and Lab Hormones (Biceter, France) to identify the nature and cellular distribution of nuclear steroid receptors in isolated specific cell types of BPH. In Chicago, technics for isolating viable prostate cells by various methods will be undertaken, including suprafusion of tissue fragments with appropriate tissue disaggregating enzymes. Stromal and epithelial cells will be separated by gradient fractionation. These cell studies will be correlated with light and electron microscopy. "Enzyme" markers for cell types and suitable steroid receptor assay conditions will be defined at Bicetre. Optimal methods once developed, will then be routinely applied to BPH samples at both Chicago and Bicetre. The steroid receptor results obtained on isolated prostate cells will be correlated with cell morphology in BPH samples. In Chicago, the nature and distribution of steroid receptor in the cells of "normal" prostate, both from the peripheral as well as periurtheral portions of the gland will also be studied. Finally, nuclear steroid receptors in the specific cell types isolated from prostatic cancer samples will be examined in Chicago.